A plasma display panel (hereinafter referred to as “panel”), among thin image display elements, allows high speed display and can be easily enlarged, so that the panel becomes commercially practical as a large-screen display device.
The panel is formed by sticking a front plate to a back plate. The front plate has the following elements:                a glass substrate;        display electrode pairs that are disposed on the glass substrate and each of which is formed of a scan electrode and a sustain electrode;        a dielectric layer formed so as to cover the display electrode pairs; and        a protective layer formed on the dielectric layer.The protective layer protects the dielectric layer from ion collision and facilitates discharge.        
The back plate has the following elements:                a glass substrate;        data electrodes formed on the glass substrate;        a dielectric layer for covering the data electrodes;        barrier ribs formed on the dielectric layer; and        phosphor layers that are disposed between the barrier ribs and emit red, green, and blue lights, respectively.The front plate and back plate are faced to each other so that the display electrode pairs intersect with the data electrodes while discharge space is sandwiched, and their periphery is sealed with low-melting glass. Discharge gas containing xenon is filled into the discharge space. Discharge cells are formed in the parts where the display electrode pairs face the data electrodes.        
In a plasma display device using the panel having this structure, a gas discharge is selectively caused in respective discharge cells of the panel, ultraviolet rays generated at this time excite red, green, and blue phosphors to emit lights, and thus color display is attained.
A subfield method is generally used as a method of driving the panel. In this method, one field period is divided into a plurality of subfields, and the subfields in which light is emitted are combined, thereby performing gradation display. Each subfield has an initializing period, an address period, and a sustain period. In the initializing period, a predetermined voltage is applied to the scan electrodes and the sustain electrodes to cause the initializing discharge, and wall charge required for a subsequent address operation is produced on each electrode. In the address period, a scan pulse is sequentially applied to the scan electrodes, and an address pulse is selectively applied to the data electrodes to cause address discharge, thereby producing wall charge. In the sustain period, a sustain pulse is alternately applied to the display electrode pairs, a sustain discharge is selectively caused in the discharge cells, and a phosphor layer of the corresponding discharge cell is light-emitted, thereby displaying an image.
In order to display a high-quality image by controlling the panel so that light emission is secured in a discharge cell to emit light and no light emission is secured in a discharge cell to emit no light, a certain address operation is required within an assigned time. For this purpose, a panel capable of being driven at a high speed has been developed, and a driving method and driving circuit for exploiting the performance of the panel and displaying a high-quality image have been studied.
The discharge characteristic of the panel largely depends on the characteristic of the protective layer. Especially, in order to improve the electron emission performance and charge retention performance that affect the possibility of the high speed driving, the material, structure, and manufacturing method of the protective layer have been studied widely. Patent literature 1, for example, discloses a plasma display device having the following elements:                a panel having a magnesium oxide layer that is produced by gas phase oxidation of magnesium vapor and has a cathode luminescence emission peak at a wavelength of 200 to 300 nm; and        an electrode driving circuit for sequentially applying a scan pulse to one electrode of each of the display electrode pairs constituting all display lines in the address period and applying, to the data electrode, the address pulse corresponding to the display line to which the scan pulse is applied.        
Recently, a plasma display device having a large screen and high definition has been demanded. For example, a high definition plasma display device having 1920 pixels and 1080 lines has been demanded, further an extremely high definition plasma display device having 2160 lines or 4320 lines has been demanded. While the number of lines is increased, the number of subfields for displaying the smooth gradation needs to be secured. Therefore, the time assigned to the address operation per line is apt to become increasingly shorter. In order to perform a certain address operation within the assigned time, a plasma display device is demanded that has a panel allowing stabler and higher-speed address operation than that of the conventional art, its driving method, and a driving circuit for achieving it.    [Patent Literature 1] Unexamined Japanese Patent Publication No. 2006-54158